Change-speed gear



Aug. l7

. E. J- KNAPP CHANGE SPEED GEAR 2 Sheets -Sheet 1 ATTORNEY Filed June 13, 1925 E. J. KNAPP CHANGE SPEED GEAR 1 Al w mm m uwl H mm mwwkmww 4! ATTORNEY Patented Aug. 17, 1926.

PATENT oFricE.

EDWARD J. KNAPP, OF KANSAS CITY, MISSOURI.

CHANGE-SPEED GEAR.

Applicationfilecl June 13, 1925. Serial No. 36,908.

This invention relates to change speed mechanism, the primary object being to vary the speed of a driven shaft with re spect to a driving shaft Without throwing gears into and out of mesh.

One of the main objections to the standard shifting mechanism used on motor vehicles is that in shifting, certain gears are thrown out of mesh and certain other gears are thrown into mesh, and unless the shifts are made at the proper time the gears clash.

. Another disadvantage of the standard gear shift mechanism is that the clutch which connects the drive shaft of the motor to the driven shaft must be thrown out so that these two shafts are disconnected when changing from one speed to another, and in view of the necessity for disconnecting certain gears when other gears are brought into mesh, it is practical to have only three speeds forward and onereverse. lVith my invention it is possible to have an infinite number of forward speeds and a number of reverse speeds, but ordinarily two reverse speeds will be sufficient for all practical purposes.

According to my invention all of the gears on the driven shaft are in mesh with the gears on the drive shaft. One of the shafts, usually the driven shaft, is hollow, and on it loosely mounted is a plurality of gears which may be keyed to the shaft on which they are mounted by a longitudinally movable shifter, so that any one gear may be selected as part of the mechanism for transmitting power from the drive shaft to the driven shaft. A

Since the selector or shifter moves rectilineally within one of the shafts, it is obvious that the number of speeds at which the driven shaft may be rotated will be governed by the length of the shaft and the amplitude of movements of the selector.

The novelty of the invention will be un derstood by reference to the following description in connection with the acpompanying drawings, in which Fig. 1 is a perspective view of a change speed mechanism constructed in accordance with my invention, parts being broken away to illustrate the construction within the hollow shaft.

Fig. 2 is a cross sectional view showing a set of reversing gears in elevation.

Fig. 3 is a fragmentary perspective view of the hollow shaft, one of the selective gears, and one of the dogs and its actuating mechanism for engagement with the gear.

Fig. 4 is a longitudinal sectional view through part of the hollow shaft, showing one of the dogs in retracted position.

Fig. 5 is a like view showing one of the dogs in projected position to engage a notch in its gear, and

Fig. 6 is a like view showing the dog in slot engaging position with respect to its gear.

Referring now to the drawings by numerals of reference, 1 and 2 designate two parallel shafts, one of which is to be driven at a variable speed with respect to the other. Either shaft may be the drive shaft, but for convenience I will hereinafter refer to the shaft 1 as the drive shaft and the shaft 2 as the driven shaft.

The driven shaft and the drive shaft may be mounted in suitable bearings in a case into which appropriate lubricant may be introduced. On the drive shaft 1 is a plurality of gears 4:, 5, 6, 7, 8, 9, 10 and 11 of diflerent diameters. These are keyed or otherwise secured to the shaft 1 in an ap propriate manner. The shaft 1 will be driven at a relatively uniform speed, and

while the motor is operating it will be constantly rotating. Therefore all of the gears a to 11 will be constantly rotating. The shaft 2 will be appropriately connected to the driving axles of the vehicle. It will not rotate unless one of the selected gears 12, 13, 14, 15, 16, 17, 18, or 19 is made rigid with respect to the shaft2. The mechanism for connecting and discnnecting the shaft 2 to the gears 12 to 19, both inclusive, is the important part of my invention. By reference to the drawings it will be observed that the gears 12 to 19 are held in predetermined spaced relation by collars 20 which are fast on the shaft 2, and between which the gears 12 to 19 are located.

The shaft 2 has a plurality of elongated slots 21 through which the teeth 22 of the dogs 23 may project to engage notches 24 in the gears 12 to 19. The dogs 23 consist of flat plates 25 which carry the teeth 22'. Between the inner faces of the plates 25 and the spring compression plates 26 are coil springs 27 and 28. These bear against the inner faces of the plates 25 and are seated in recesses 29 and 30 in the plates 26. On top of the plates 25 are springs 31 and 32. These are weaker than the springs 27 and 28 and they are received in recesses 33 and 34 in the adjusting screws and 36 carried by the collars so that the screws 35 and 36 can vary the compression of the springs 31 and 32, so that the springs will normally hold the dogs 23 out of engagement with the gears 12 to 19. The bottom faces of the platesor blocks 26 are curved, especially their ends 3}; and 38, the bottom faces of the members 26 riding upon a longitudinally slidableshiftrod39 having a selector in the form of an enlargementgor collar about the periphery of the rodwhich is adapted to move against the inner face or bottom ofthe m'ember26 to put the springs 27 and 28 under compression so that. they will preponderate overthe" springs 31 and 32 and thereby exert a'radi al' and outward movement to the selected dog to cause its tooth 22 to move against the inner face of its loose gear until thelnotchor slot 24 registers with the tooth 221Whereupon the t'ooth will snap into. the slot or notch and cause the' selected gear to rotate: with the shaft 2, the result being that the shaft 2 will be driven-at av speedzdetermined b y the diameter of the selected gear.

When the selector: or collar 40 is moved out of engagement with one of the members 26, that is, when it is between anytwo memhers or. gears on shaftc2, the change speed gear will be in neutral. That is, the? drive shaft mayrotate, rotating the gears 12-,to 19.

without" rotating the shaft 2,: and: conses quently the driven shaft; will not be turned. The rod 39 may be shifted longitudinally by. afihange speed gear shift lever 41 ,piv'otedat l-2a-nd having a spring-pressed pawl 43pto' engage teeth on therac n44; the pawl being withdrawnby the pivoted member 45 and the rod, 4' 6 in a mannercommon to ratchet levers. Thelever 11 is fastened to the rod 39, by a link; 47 in anappropriate manner. The gears 10, 11, 18 and19 are the reverse gears. They, are not in mesh, but each set meshes with a back gear148 on a stub shaft 19 that is, thereis a separatetgeaf 48 for each :setof; reverse gears10 -'1'8} and l1,19.'

Then; the'pa-rts; are properly assembled:v with the selector or-collar 450i infneutra-l position, and-the drive shaftis' turning, no motion-will be imparted to the' drivenxshaftbecause the' springs 31" a:ndq,32-' being undercompression, will tend to force the-plates 25 towardthe axis of the shaft 2,: as indicated in Figure 4: The springs 27 and 28 at this time will not be under compression, so it may be said that thesprings 31 and 32 preponderate over the springs 27 and 28:

Vhen it is desired to throw ,the gears into mesh the rod 39 is moved longitudinally, preferably fthrough the gear from low to the gear selected for the cruising-speed, and as the collar 40 ridesover the bottom face. of each member 26, the-springs 27 and 28 will he put under compression, preponderatmesh with gears 11 and 19 will have the doublesprings,,one set weaker than the other,: the

same; effect, By providing the dogs for the respective loose gears will1be caused to float in: the' shaft' 2, that is, they will have no fixedpositions, but soon as the selectoror, collar 40 has hee1r1nov'ed- .behind one of the plates 26 as shown initFi'g ure's 5 and .6, then the dog selected will he'- come effective in causing its particular gear.

tobe fast to shaft 2, andzconsequent ly, willcause the shaft 2 to be driven at the selected" speed; a a

hat I;clai1nand desire to secure by Let-v ters-Patent is V In combination, a; driveshaft and. a driven snaft, one of which isholl-ow, phi"- ral'ityof gears loose onthe hollow shaft; a:

plurality of dogs in the hollow shaft, each dog comprising a flat: plate having a tooth" projectable through aislot in thewhollow shaft to engage a notch in one of'the'loose gears, .a plate spaced from" the inner face of each-dog, springsbetween theonter face of each dog and the wall of the, hollow shaft, springs between-the. two plates,;a-nd a selector: in the hollow shaft slidable over the inner plates to compress the spring to urge the dogs into loosegear-engaginggpo sitions', and gears on the other shaft in mesh with the loose gears.

2., A drive shaft,a driven shaft, one-of-tliei:

shafts being hollow andhaving, a sloti'n its wall, a-i gea-r loose on the hollow shaft; :1 gean fixed to the other shaft .in mesh with the loose gear, a fiat plate within the hollow shaft, a tooth i itermediate the ends of the flat plate to engage a notch in the loose? gear, another plate within. the hollowshaft parallel'with the first, yielding means be-' tween the first plate and the wallof the hollow shaft, yielding means between the two plates, andv means slidable in the hollow shaft to urgethe secondplate toward the first.

3 A; drive shaft, a driven shaft, one

the shafts. being hollow and having asl'ot in its wall, a gear loose onthe hollowshaft, v a gear fixed to the other shaft in mesh-with.

thel'oose gear, a loose-gear engaging dog within the hollow shaft, yielding meansbctween the dog and the wall of the shaft, a member located'finwa-rdly from the dog, yielding; means between the member and the dog, and means for urging the- 1'nember radially toward the wall of the hollow shaft to compress both yielding means to urge the dog into gear-engaging position.

4:. A drive shaft, a driven shaft, one of the shafts being hollow and having a slot in its wall, a gear loose on the hollow shaft, a gear fixed on the other shaft in mesh with the loose gear, a loose-gear engaging dog within the hollow shaft, a spring between the dog and the wall of the hollow shaft, a member between the dog and the axial center of the hollow shaft, a spring between the member and the dog, the strength of One of the springs preponderating over the strength of the other, and means for urging the member toward the dog in opposition to the springs.

5. A drive shaft, a driven shaft, one of the shafts being hollow and having a slot in its wall, a gear loose on the hollow shaft, a gear fixed on the other shaft in mesh with the loose gear, a loose-gear engaging dog within the hollow shaft, a spring between the dog and the wall of the hollow shaft, a member between the dog and the axial center of the hollow shaft, a spring between the member and the dog, the strength of the spring between the seat and the member being greater than that of the spring between the dog and the hollow shaft, and means for urging the member toward the dog.

6. A drive shaft, a driven shaft, one of the shafts being hollow and having a slot in its wall, a gear loose on the hollow shaft, a gear fixed on the other shaft in mesh with the loose gear, a loose-gear engaging dog within the hollow shaft, a spring between the dog and the wall of the hollow shaft,

a member between the dog and the axial center of the hollow shaft, a spring between the member and the dog, the strength of the spring between the seat and the member being greater than that of the spring between the dog and the hollow shaft, means for urging the member toward the dog, and means for achustmg one set of springs.

In testimony whereof I afiixmy signature.

EDWARD J. KNAPP. 

